Fibrous materials and composites

ABSTRACT

Fibrous materials, compositions that include fibrous materials, and uses of the fibrous materials and compositions are disclosed. For example, the fibrous materials can be operated on by a microorganism to produce ethanol or a by-product, such as a protein or lignin.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation (and claims benefit of priority under35 U.S.C. §120), of U.S. application Ser. No. 13/162,225, filed Jun. 16,2011, which is a continuation of U.S. application Ser. No. 12/769,931,filed on Apr. 29, 2010 and now U.S. Pat. No. 7,980,495, which was adivisional of U.S. application Ser. No. 11/453,951, filed on Jun. 15,2006 and now U.S. Pat. No. 7,708,214, which was a continuation-in-part(CIP) of, and claimed the benefit of priority from, InternationalApplication No. PCT/US2006/010648, filed on Mar. 23, 2006, which claimedbenefit of U.S. Provisional Patent Application Ser. Nos. 60/664,832,filed Mar. 24, 2005, 60/688,002, filed Jun. 7, 2005, 60/711,057, filedAug. 24, 2005, 60/715,822, filed Sep. 9, 2005, 60/725,674, filed Oct.12, 2005, 60/726,102, filed Oct. 12, 2005, and 60/750,205, filed Dec.13, 2005. The entire content of each of these applications is herebyincorporated by reference herein.

TECHNICAL FIELD

This invention relates to fibrous materials and to compositions.

BACKGROUND

Fibrous materials, e.g., cellulosic and lignocellulosic materials, areproduced, processed, and used in large quantities in a number ofapplications. Often such fibrous materials are used once, and thendiscarded as waste.

Various fibrous materials, their uses and applications have beendescribed in U.S. Pat. Nos. 6,448,307, 6,258,876, 6,207,729, 5,973,035and 5,952,105. The entire disclosure of each of the patents of thisparagraph is incorporated by reference herein.

SUMMARY

Generally, this invention relates to fibrous materials, methods ofmaking fibrous materials, compositions that include fibrous materials(e.g., composites that include the fibrous materials and a resin, orcompositions that include the fibrous materials and bacteria and/or anenzyme), and to uses of the same. For example, the compositions can beused to make ethanol, or a by-product, such as a protein or lignin, orapplied to a structure as insulation.

Any of the fibrous materials disclosed herein can be used in combinationwith any of the fibrous materials, resins, additives, or othercomponents disclosed in U.S. Pat. Nos. 6,448,307, 6,258,876, 6,207,729,5,973,035 and 5,952,105. In turn, these fibrous materials and/orcomponents can be used in any of the applications, products, procedures,et cetera disclosed in any of these patents or in this application.

The fibrous materials or compositions that include the fibrous materialscan be, e.g., associated with, blended with, adjacent to, surrounded by,or within a structure or carrier (e.g., a netting, a membrane, aflotation device, a bag, a shell, or a biodegradable substance).Optionally, the structure or carrier may itself be made from a fibrousmaterial, or of a composition that includes a fibrous material. In someembodiments, the fibrous material is combined with a material, such as aprotic acid, that enhances the rate of biodegradation of the fibrousmaterial. In some embodiments, the fibrous material is combined with amaterial that retards degradation of the fibrous material, such as abuffer.

The ratio of fibrous materials to the other components of thecompositions will depend upon the nature of the components, and can bereadily adjusted for a specific product application.

Any of the fibrous materials described herein, including any of thefibrous materials made by any of the methods described herein, can beused, e.g., to form composites with resin, or can be combined withbacteria and/or one or more enzymes to produce a valuable product, suchas a fuel (e.g., ethanol, a hydrocarbon, or hydrogen).

In one aspect, the invention features methods of making fibrousmaterials. The methods include shearing a fiber source to provide afirst fibrous material, and passing the first fibrous material through afirst screen having an average opening size of 1.59 mm or less ( 1/16inch, 0.0625 inch) to provide a second fibrous material. The fibersource can, e.g., be cut into pieces or strips of confetti-like materialprior to the shearing.

In some embodiments, the average opening size of the first screen isless than 0.79 mm ( 1/32 inch, 0.03125 inch), e.g., less than 0.40 mm (1/64 inch, 0.015625 inch), less than 0.20 mm ( 1/128 inch, 0.0078125inch), or even less than 0.10 mm ( 1/256 inch, 0.00390625 inch).

In specific implementations, the shearing is performed with a rotaryknife cutter. If desired, the shearing can be performed while the fibersource is dry (e.g., having less than 0.25 percent by weight absorbedwater), hydrated, or even while the fiber source is partially or fullysubmerged in a liquid, such as water or isopropanol.

The second fibrous material can, e.g., be collected in a bin having apressure below nominal atmospheric pressure, e.g., at least 10 percentbelow nominal atmospheric pressure, at least 50 percent below nominalatmospheric pressure, or at least 75 percent below nominal atmosphericpressure.

The second fibrous material can, e.g., be sheared once or numeroustimes, e.g., twice, thrice, or even more, e.g., ten times. Shearing can“open up” and/or “stress” the fibrous materials, making the materialsmore dispersible, e.g., in a solution or in a resin.

The second fibrous material can be, e.g., sheared and the resultingfibrous material passed through the first screen.

The second fibrous material can be sheared, and the resulting fibrousmaterial passed through a second screen having an average opening sizeless than the first screen, providing a third fibrous material.

A ratio of an average length-to-diameter ratio of the second fibrousmaterial to an average length-to-diameter ratio of the third fibrousmaterial can be, e.g., less than 1.5, less than 1.4, less than 1.25, oreven less than 1.1.

The second fibrous can be, e.g., passed through a second screen havingan average opening size less than the first screen.

The shearing and passing can be, e.g., performed concurrently.

The second fibrous material can have an average length-to-diameter ratioof, e.g., greater than 10/1, greater than 25/1, or even greater than50/1.

For example, an average length of the second fibrous material can bebetween 0.5 mm and 2.5 mm, e.g., between 0.75 mm and 1.0 mm. Forexample, an average width of the second fibrous material can be between5 μm and 50 μm, e.g., between 10 μm and 30 μm.

A standard deviation of a length of the second fibrous material can beless than 60 percent of an average length of the second fibrousmaterial, e.g., less than 50 percent of an average length of the secondfibrous material.

In some embodiments, a BET surface area of the second fibrous materialis greater than 0.5 m2/g, e.g., greater than 1.0 m2/g, greater than 1.5m2/g, greater than 1.75 m2/g, greater than 2.5 m2/g, greater than 10.0m2/g, greater than 25.0 m2/g, greater than 50.0 m2/g, or even greaterthan 100.0 m2/g.

In some embodiments, a porosity of the second fibrous material isgreater than 25 percent, e.g., greater than 50 percent, greater than 75percent, greater than 85 percent, greater than 90 percent, greater than92 percent, greater than 95 percent, or even greater than 99 percent.

In specific embodiments, the screen is formed by interweavingmonofilaments.

The fiber source can include, e.g., a cellulosic material, alignocellulosic material.

In some embodiments, the fiber source includes a blend of fibers, e.g.,fibers derived from a paper source and fibers derived from a textilesource, e.g., cotton.

In another aspect, the invention features methods of making fibrousmaterials that include shearing a fiber source to provide a firstfibrous material; and passing the fibrous material through a firstscreen to provide a second fibrous material. A ratio of an averagelength-to-diameter ratio of the first fibrous material to an averagelength-to-diameter of the second fibrous material is less than 1.5.

In another aspect, the invention features methods of making fibrousmaterials that include shearing a fiber source to provide a firstfibrous material; passing the fibrous material through a first screen toprovide a second fibrous material; and then shearing the second fibrousmaterial again to provide a third fibrous material.

In another aspect, the invention features composites or compositionsmade from any of the fibrous materials described herein. For example,compositions can include any of the fibrous materials described hereinand a bacterium and/or an enzyme. The compositions that include any ofthe fibrous materials described herein and the bacterium and/or enzymecan be in a dry state, or they can include a liquid, such as water.

For example, the composite can be in the form of a stepping stool,pipes, panels, decking materials, boards, housings, sheets, blocks,bricks, poles, fencing, members, doors, shutters, awnings, shades,signs, frames, window casings, backboards, flooring, tiles, railroadties, trays, tool handles, stalls, films, wraps, tapes, boxes, baskets,racks, casings, binders, dividers, walls, mats, frames, bookcases,sculptures, chairs, tables, desks, toys, games, pallets, wharves, piers,boats, masts, septic tanks, automotive panels, computer housings, above-and below-ground electrical casings, furniture, picnic tables, benches,shelters, trays, hangers, servers, caskets, book covers, canes andcrutches.

In another aspect, the invention features fibrous materials having anaverage length-to-diameter ratio of greater than 5, and having astandard deviation of a fiber length of less than sixty percent of anaverage fiber length.

For example, the average length-to-diameter ratio can be greater than10/1, e.g., greater than 15/1, greater than 25/1, greater than 35/1,greater than 45/1, or even greater than 50/1.

For example, the average length can be between 0.5 mm and 2.5 mm.

In another aspect, the invention features methods of making fibrousmaterials that include shearing a fiber source to provide a firstfibrous material; collecting the first fibrous material; and thenshearing the first fibrous to provide a second fibrous material.

In another aspect, the invention features methods of making a usefulmaterial, such as a fuel. The methods include shearing a fiber source toprovide a first fibrous material; passing the first fibrous materialthrough a first screen having an average opening size of about 1.59 mmor less ( 1/16 inch, 0.0625 inch) to provide a second fibrous material;and combining the second fibrous material with a bacterium and/orenzyme, the bacterium and/or enzyme utilizing the second fibrousmaterial to produce a fuel that includes hydrogen, an alcohol, anorganic acid and/or a hydrocarbon.

The alcohol can be, e.g., methanol, ethanol, propanol, isopropanol,butanol, ethylene glycol, propylene glycol, 1,4-butane diol, glycerin,or mixtures of these alcohols; the organic acid can be, e.g., malonicacid, succinic acid, glutaric acid, oleic acid, linoleic acid, glycolicacid, lactic acid, γ-hydroxybutyric acid, or mixtures of these acids;and the hydrocarbon can be, e.g., methane, ethane, propane, isobutene,pentane, n-hexane, or mixtures of these hydrocarbons.

Prior to combining with the bacterium and/or enzyme, any of the fibrousmaterials described herein can be hydrolyzed to break down highermolecular weight carbohydrates into lower molecular weightcarbohydrates.

In another aspect, the invention features methods of making a usefulmaterial, such as a fuel, by shearing a fiber source or a fibrousmaterial, and then combining it with a bacterium and/or an enzyme. Forexample, the fiber source can be sheared once to provide a fibrousmaterial, and then the fibrous material can be combined with a bacteriumand/or an enzyme to make the useful material.

In another aspect, the invention features methods of densifying fibrouscompositions. The methods include shearing a fiber source to provide afibrous material;

combining the fibrous material with a bacterium and/or enzyme to providea fibrous material composition; encapsulating the composition in asubstantially gas impermeable material; and removing entrapped gas fromthe encapsulated composition to densify the composition. For example,the gas impermeable material can be in the form of a bag, and thecomposition can be densified by evacuating air from the bag, and thensealing the bag.

In another aspect, the invention features composites that include afibrous material, a resin and a dye.

For example, the fibrous material can have an average length-to-diameterratio of greater than 5, and a standard deviation of a fiber length ofless than sixty percent of an average fiber length.

In some embodiments, the composite additionally includes a pigment.

In some implementations, the dye soaked into or surfaced on the fibers.

In another aspect, the invention features methods of making compositesthat include dyeing a fibrous material; combining the fibrous materialwith a resin; and

forming a composite from the combination.

In another aspect, the invention features methods of making compositethat include adding a dye to a resin to provide a dye/resin combination;combining the dye/resin combination with a fibrous material; and forminga composite from the dye/resin combination and fibrous material.

The term “fibrous material”, as used herein, is a material that includesnumerous loose, discrete and separable fibers. For example, a fibrousmaterial can be prepared from a polycoated paper or a bleached Kraftpaper fiber source by shearing, e.g., with a rotary knife cutter.

The term “screen”, as used herein, means a member capable of sievingmaterial according to size, e.g., a perforated plate, cylinder or thelike, or a wire mesh or cloth fabric.

Embodiments and/or aspects can have any one of, or combinations of, thefollowing advantages. The fibrous materials are opened up and/orstressed, making the materials more dispersible, e.g., in a solution orin a resin, and making them more susceptible to chemical, enzymatic orbiological attack. The fibrous materials can have, e.g., a relativelynarrow length and/or length-to-diameter ratio distribution, such thattheir properties are consistently defined. For example, when blendedwith a molten resin or a solution, the fibers of the fibrous materialscan modify the rheology of the molten resin or solution in a consistentand predicable manner, e.g., resulting in resin/fibrous materialcombinations that are, e.g., easier to mold and extrude. For example,the fibrous materials can easily pass through small openings orchannels, such as those found in or associated with injection molds,e.g., gates or hot runners. Parts molded from such fibrous materials canexhibit a good surface finish, e.g., with few visible speckles of largeparticles and/or agglomerated particles.

All publications, patent applications, patents, and other referencesmentioned herein are incorporated by reference in their entirety for allthat they contain.

Other features and advantages of the invention will be apparent from thefollowing detailed description, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is block diagram illustrating conversion of a fiber source into afirst and second fibrous material.

FIG. 2 is a cross-sectional view of a rotary knife cutter.

FIGS. 3-8 are top views of a variety of screens made from monofilaments.

FIG. 9 is block diagram illustrating conversion of a fiber source into afirst, second and third fibrous material.

FIGS. 10A and 10B are photographs of fiber sources; FIG. 10A being aphotograph of a polycoated paper container, and FIG. 10B being aphotograph of unbleached Kraft paper rolls.

FIGS. 11 and 12 are scanning electron micrographs of a fibrous materialproduced from polycoated paper at 25× magnification and 1000×magnification, respectively. The fibrous material was produced on arotary knife cutter utilizing a screen with ⅛ inch openings.

FIGS. 13 and 14 are scanning electron micrographs of a fibrous materialproduced from bleached Kraft board paper at 25× magnification and 1000×magnification, respectively. The fibrous material was produced on arotary knife cutter utilizing a screen with ⅛ inch openings.

FIGS. 15 and 16 are scanning electron micrographs of a fibrous materialproduced from bleached Kraft board paper at 25× magnification and 1000×magnification, respectively. The fibrous material was twice sheared on arotary knife cutter utilizing a screen with 1/16 inch openings duringeach shearing.

FIGS. 17 and 18 are scanning electron micrographs of a fibrous materialproduced from bleached Kraft board paper at 25× magnification and 1000×magnification, respectively. The fibrous material was thrice sheared ona rotary knife cutter. During the first shearing, a ⅛ inch screen wasused; during the second shearing, a 1/16 inch screen was used, andduring the third shearing a 1/32 inch screen was used.

FIG. 19 is a block diagram illustrating revertible bulk densification ofa fibrous material composition.

DETAILED DESCRIPTION

Referring to FIG. 1, a fiber source 10 is sheared, e.g., in a rotaryknife cutter, to provide a first fibrous material 12. The first fibrousmaterial 12 is passed through a first screen 16 having an averageopening size of 1.59 mm or less ( 1/16 inch, 0.0625 inch) to provide asecond fibrous material 14. If desired, fiber source 10 can be cut priorto the shearing, e.g., with a shredder. For example, when a paper isused as the fiber source 10, the paper can be first cut into strips thatare, e.g., ¼- to ½-inch wide, using a shredder, e.g., a counter-rotatingscrew shredder, such as those manufactured by Munson (Utica, N.Y.). Asan alternative to shredding, the paper can be reduced in size by cuttingto a desired size using a guillotine cutter. For example, the guillotinecutter can be used to cut the paper into sheets that are, e.g., 10inches wide by 12 inches long.

In some embodiments, the shearing of fiber source 10 and the passing ofthe resulting first fibrous material 12 through first screen 16 areperformed concurrently. The shearing and the passing can also beperformed in a batch-type process.

For example, a rotary knife cutter can be used to concurrently shear thefiber source 10 and screen the first fibrous material 12. Referring toFIG. 2, a rotary knife cutter 20 includes a hopper 22 that can be loadedwith a shredded fiber source 10′ prepared by shredding fiber source 10.Shredded fiber source 10′ is sheared between stationary blades 24 androtating blades 26 to provide a first fibrous material 12. First fibrousmaterial 12 passes through screen 16 having the dimensions describedabove, and the resulting second fibrous material 14 is captured in bin30. To aid in the collection of the second fibrous material 14, bin 30can have a pressure below nominal atmospheric pressure, e.g., at least10 percent below nominal atmospheric pressure, e.g., at least 25 percentbelow nominal atmospheric pressure, at least 50 percent below nominalatmospheric pressure, or at least 75 percent below nominal atmosphericpressure. In some embodiments, a vacuum source 50 (FIG. 2) is utilizedto maintain the bin below nominal atmospheric pressure.

Shearing can be advantageous for “opening up” and “stressing” thefibrous materials, making the materials more dispersible, e.g., in asolution or in a resin, and making them more susceptible to chemical,enzymatic or biological attack. Without wishing to be bound by anyparticular theory, it is believed, at least in some embodiments, thatshearing can functionalize fiber surfaces with functional groups, suchas hydroxyl or carboxylic acid groups, which can, e.g., help dispersethe fibers in a molten resin or enhance chemical or biological attack.

The fiber source can be sheared in a dry state, a hydrated state (e.g.,having up to ten percent by weight absorbed water), or in a wet state,e.g., having between about 10 percent and about 75 percent by weightwater. The fiber source can even be sheared while partially or fullysubmerged under a liquid, such as water, ethanol, isopropanol.

The fiber source can also be sheared in under a gas (such as a stream oratmosphere of gas other than air), e.g., oxygen or nitrogen, or steam.

Other methods of making the fibrous materials include stone grinding,mechanical ripping or tearing, pin grinding or air attrition milling.

If desired, the fibrous materials can be separated, e.g., continuouslyor in batches, into fractions according to their length, width, density,material type, or some combination of these attributes. For example, forforming composites, it is often desirable to have a relatively narrowdistribution of fiber lengths. In addition, e.g., when makingcompositions that include bacteria and/or an enzyme, it is oftendesirable to use a substantially single material as a feedstock.

For example, ferrous materials can be separated from any of the fibrousmaterials by passing a fibrous material that includes a ferrous materialpast a magnet, e.g., an electromagnet, and then passing the resultingfibrous material through a series of screens, each screen havingdifferent sized apertures.

The fibrous materials can also be separated, e.g., by using a highvelocity gas, e.g., air. In such an approach, the fibrous materials areseparated by drawing off different fractions, which can be characterizedphotonically, if desired. Such a separation apparatus is discussed inLindsey et al, U.S. Pat. No. 6,883,667, the entire disclosure of whichis hereby incorporated by reference herein in its entirety.

The fibrous materials can be used immediately following theirpreparation, or they can may be dried, e.g., at approximately 105° C.for 4-18 hours, so that the moisture content is, e.g., less than about0.5% before use.

If desired, lignin can be removed from any of the fibrous materials thatinclude lignin, such as lignocellulosic materials. Also, if desired, thefibrous material can be sterilized to kill any microorganisms that maybe on the fibrous material. For example, the fibrous material can besterilized by exposing the fibrous material to radiation, such asinfrared radiation, ultraviolet radiation, or an ionizing radiation,such as gamma radiation. The fibrous materials can also be sterilized bytemperature adjustment, e.g., heating or cooling the fibrous materialunder conditions and for a sufficient time to kill any microorganisms,or by employing a chemical sterilant, such as bleach (e.g., sodiumhypochlorite), chlorhexidine, or ethylene oxide. The fibrous materialscan also be sterilized by using a competitive organism, such as yeastagainst bacteria.

Referring to FIGS. 3-8, in some embodiments, the average opening size ofthe first screen 16 is less than 0.79 mm ( 1/32 inch, 0.03125 inch),e.g., less than 0.51 mm ( 1/50 inch, 0.02000 inch), less than 0.40 mm (1/64 inch, 0.015625 inch), less than 0.23 mm (0.009 inch), less than0.20 mm ( 1/128 inch, 0.0078125 inch), less than 0.18 mm (0.007 inch),less than 0.13 mm (0.005 inch), or even less than less than 0.10 mm (1/256 inch, 0.00390625 inch). Screen 16 is prepared by interweavingmonofilaments 52 having an appropriate diameter to give the desiredopening size. For example, the monofilaments can be made of a metal,e.g., stainless steel. As the opening sizes get smaller, structuraldemands on the monofilaments may become greater. For example, foropening sizes less than 0.40 mm, it can be advantageous to make thescreens from monofilaments made from a material other than stainlesssteel, e.g., titanium, titanium alloys, amorphous metals, nickel,tungsten, rhodium, rhenium, ceramics, or glass. In some embodiments, thescreen is made from a plate, e.g. a metal plate, having apertures, e.g.,cut into the plate using a laser.

In some embodiments, the second fibrous 14 is sheared and passed throughthe first screen 16, or a different sized screen. In some embodiments,the second fibrous material 14 is passed through a second screen havingan average opening size equal to or less than that of first screen 16.

Referring to FIG. 9, a third fibrous material 62 can be prepared fromthe second fibrous material 14 by shearing the second fibrous material14 and passing the resulting material through a second screen 60 havingan average opening size less than the first screen 16.

Fiber sources include cellulosic fiber sources, including paper andpaper products like those shown in FIGS. 10A (polycoated paper) and 10B(Kraft paper), and lignocellulosic fiber sources, including wood, andwood-related materials, e.g., particle board. Other suitable fibersources include natural fiber sources, e.g., grasses, rice hulls,bagasse, cotton, jute, hemp, flax, bamboo, sisal, abaca, straw, corncobs, rice hulls, coconut hair; fiber sources high in α-cellulosecontent, e.g., cotton; synthetic fiber sources, e.g., extruded yarn(oriented yarn or un-oriented yarn) or carbon fiber sources; inorganicfiber sources; and metal fiber sources. Natural or synthetic fibersources can be obtained from virgin scrap textile materials, e.g.,remnants or they can be post consumer waste, e.g., rags. When paperproducts are used as fiber sources, they can be virgin materials, e.g.,scrap virgin materials, or they can be post-consumer waste. Aside fromvirgin raw materials, post-consumer, industrial (e.g., offal), andprocessing waste (e.g., effluent from paper processing) can also be usedas fiber sources. Also, the fiber source can be obtained or derived fromhuman (e.g., sewage), animal or plant wastes. Additional fiber sourceshave been described in U.S. Pat. Nos. 6,448,307, 6,258,876, 6,207,729,5,973,035 and 5,952,105, each of which is incorporated by referenceherein in its entirety.

Blends of any of the above fibrous sources may be used.

Generally, the fibers of the fibrous materials can have a relativelylarge average length-to-diameter ratio (e.g., greater than 20-to-1),even if they have been sheared more than once. In addition, the fibersof the fibrous materials described herein may have a relatively narrowlength and/or length-to-diameter ratio distribution. Without wishing tobe bound by any particular theory, it is currently believed that therelatively large average length-to-diameter ratio and the relativelynarrow length and/or length-to-diameter ratio distribution are, at leastin part, responsible for the ease at which the fibrous materials aredispersed in a resin, e.g., a molten thermoplastic resin. It is alsobelieved that the relatively large average length-to-diameter ratio andthe relatively narrow length and/or length-to-diameter ratiodistribution are, at least in part, responsible for the consistentproperties of the fibrous materials, the predictable rheologymodification the fibrous materials impart on a resin, the ease at whichthe combinations of the fibrous materials and resins are cast, extrudedand injection molded, the ease in which the fibrous materials passthrough small, often torturous channels and openings, and the excellentsurface finishes possible with molded parts, e.g., glossy finishesand/or finishes substantially devoid of visible speckles.

As used herein, average fiber widths (i.e., diameters) are thosedetermined optically by randomly selecting approximately 5,000 fibers.Average fiber lengths are corrected length-weighted lengths. BET(Brunauer, Emmet and Teller) surface areas are multi-point surfaceareas, and porosities are those determined by mercury porosimetry.

The average length-to-diameter ratio of the second fibrous material 14can be, e.g. greater than 8/1, e.g., greater than 10/1, greater than15/1, greater than 20/1, greater than 25/1, or greater than 50/1. Anaverage length of the second fibrous material 14 can be, e.g., betweenabout 0.5 mm and 2.5 mm, e.g., between about 0.75 mm and 1.0 mm, and anaverage width (i.e., diameter) of the second fibrous material 14 can be,e.g., between about 5 μm and 50 μm, e.g., between about 10 μm and 30 μm.

In some embodiments, a standard deviation of the length of the secondfibrous material 14 is less than 60 percent of an average length of thesecond fibrous material 14, e.g., less than 50 percent of the averagelength, less than 40 percent of the average length, less than 25 percentof the average length, less than 10 percent of the average length, lessthan 5 percent of the average length, or even less than 1 percent of theaverage length.

In some embodiments, a BET surface area of the second fibrous material14 is greater than 0.1 m2/g, e.g., greater than 0.25 m2/g, greater than0.5 m2/g, greater than 1.0 m2/g, greater than 1.5 m2/g, greater than1.75 m2/g, greater than 5.0 m2/g, greater than 10 m2/g, greater than 25m2/g, greater than 35 m2/g, greater than 50 m2/g, greater than 60 m2/g,greater than 75 m2/g, greater than 100 m2/g, greater than 150 m2/g,greater than 200 m2/g, or even greater than 250 m2/g. A porosity of thesecond fibrous material 14 can be, e.g., greater than 20 percent,greater than 25 percent, greater than 35 percent, greater than 50percent, greater than 60 percent, greater than 70 percent, e.g., greaterthan 80 percent, greater than 85 percent, greater than 90 percent,greater than 92 percent, greater than 94 percent, greater than 95percent, greater than 97.5 percent, greater than 99 percent, or evengreater than 99.5 percent.

In some embodiments, a ratio of the average length-to-diameter ratio ofthe first fibrous material 12 to the average length-to-diameter ratio ofthe second fibrous material 14 is, e.g., less than 1.5, e.g., less than1.4, less than 1.25, less than 1.1, less than 1.075, less than 1.05,less than 1.025, or even substantially equal to 1.

In particular embodiments, the second fibrous material 14 is shearedagain and the resulting fibrous material passed through a second screenhaving an average opening size less than the first screen to provide athird fibrous material 62. In such instances, a ratio of the averagelength-to-diameter ratio of the second fibrous material 14 to theaverage length-to-diameter ratio of the third fibrous material 62 canbe, e.g., less than 1.5, e.g., less than 1.4, less than 1.25, or evenless than 1.1.

In some embodiments, the third fibrous material 62 is passed through athird screen to produce a fourth fibrous material. The fourth fibrousmaterial can be, e.g., passed through a fourth screen to produce a fifthmaterial. Similar screening processes can be repeated as many times asdesired to produce the desired fibrous material having the desiredproperties.

In some embodiments, the desired fibrous material includes fibers havingan average length-to-diameter ratio of greater than 5 and having astandard deviation of the fiber length that is less than sixty percentof the average length. For example, the average length-to-diameter ratiocan be greater than 10/1, e.g., greater than 25/1, or greater than 50/1,and the average length can be between about 0.5 mm and 2.5 mm, e.g.,between about 0.75 mm and 1.0 mm. An average width of the fibrousmaterial can be between about 5 μm and 50 μm, e.g., between about 10 μmand 30 μm. For example, the standard deviation can be less than 50percent of the average length, e.g., less than 40 percent, less than 30percent, less than 25 percent, less than 20 percent, less than 10percent, less than 5 percent, or even less than 1 percent of the averagelength. A desirable fibrous material can have, e.g., a BET surface areaof greater than 0.5 m2/g, e.g., greater than 1.0 m2/g, greater than 1.5m2/g, greater than 1.75 m2/g., greater than 5 m2/g, greater than 10m2/g, greater than 25.0 m2/g, greater than 50.0 m2/g, greater than 75.0m2/g, or even greater than 100.0 m2/g. A desired material can have,e.g., a porosity of greater than 70 percent, e.g., greater than 80percent, greater than 87.5 percent, greater than 90 percent, greaterthan 92.5, greater than 95, greater than 97.5, or even greater than 99percent. A particularly preferred embodiment has a BET surface area ofgreater than 1.25 m2/g and a porosity of greater than 85 percent.

Fibrous Material/Resin Composites

Composites including any of the fibrous materials or blends of any ofthe fibrous materials described herein (including any of the fibrousmaterials disclosed in U.S. Pat. Nos. 6,448,307, 6,258,876, 6,207,729,5,973,035 and 5,952,105), e.g., the first 12 or second fibrous material14, and a resin, e.g., a thermoplastic resin or a thermosetting resin,can be prepared by combining the desired fibrous material and thedesired resin. The desired fibrous material can be combined with thedesired resin, e.g., by mixing the fibrous material and the resin in anextruder or other mixer. To form the composite, the fibrous material canbe combined with the resin as the fibrous material itself or as adensified fibrous material that can be re-opened during the combiningSuch a densified material is discussed in International Application No.PCT/US2006/010648, filed on Mar. 23, 2006, the disclosure of which isincorporated herein by reference in its entirety.

Examples of thermoplastic resins include rigid and elastomericthermoplastics. Rigid thermoplastics include polyolefins (e.g.,polyethylene, polypropylene, or polyolefin copolymers), polyesters(e.g., polyethylene terephthalate), polyamides (e.g., nylon 6, 6/12 or6/10), and polyethyleneimines. Examples of elastomeric thermoplasticresins include elastomeric styrenic copolymers (e.g.,styrene-ethylene-butylene-styrene copolymers), polyamide elastomers(e.g., polyether-polyamide copolymers) and ethylene-vinyl acetatecopolymer.

In some embodiments, the thermoplastic resin has a melt flow rate ofbetween 10 g/10 minutes to 60 g/10 minutes, e.g., between 20 g/10minutes to 50 g/10 minutes, or between 30 g/10 minutes to 45 g/10minutes, as measured using ASTM 1238.

In some embodiments, compatible blends of any of the above thermoplasticresins can be used.

In some embodiments, the thermoplastic resin has a polydispersity index(PDI), i.e., a ratio of the weight average molecular weight to thenumber average molecular weight, of greater than 1.5, e.g., greater than2.0, greater than 2.5, greater than 5.0, greater than 7.5, or evengreater than 10.0.

In specific embodiments, polyolefins or blends of polyolefins areutilized as the thermoplastic resin.

Examples of thermosetting resins include natural rubber,butadiene-rubber and polyurethanes.

In addition to the desired fibrous material and resin, additives, e.g.,in the form of a solid or a liquid, can be added to the combination ofthe fibrous material and resin. For example, suitable additives includefillers such as calcium carbonate, graphite, wollastonite, mica, glass,fiber glass, silica, and talc; inorganic flame retardants such asalumina trihydrate or magnesium hydroxide; organic flame retardants suchas chlorinated or brominated organic compounds; ground constructionwaste; ground tire rubber; carbon fibers; or metal fibers or powders(e.g., aluminum, stainless steel). These additives can reinforce,extend, or change electrical, mechanical or compatibility properties.Other additives include fragrances, coupling agents, compatibilizers,e.g., maleated polypropylene, processing aids, lubricants, e.g.,fluorinated polyethylene, plasticizers, antioxidants, opacifiers, heatstabilizers, colorants, foaming agents, impact modifiers, polymers,e.g., degradable polymers, photostabilizers, biocides, antistaticagents, e.g., stearates or ethoxylated fatty acid amines. Suitableantistatic compounds include conductive carbon blacks, carbon fibers,metal fillers, cationic compounds, e.g., quaternary ammonium compounds,e.g., N-(3-chloro-2-hydroxypropyl)-trimethylammonium chloride,alkanolamides, and amines. Representative degradable polymers includepolyhydroxy acids, e.g., polylactides, polyglycolides and copolymers oflactic acid and glycolic acid, poly(hydroxybutyric acid),poly(hydroxyvaleric acid), poly[lactide-co-(e-caprolactone)],poly[glycolide-co-(e-caprolactone)], polycarbonates, poly(amino acids),poly(hydroxyalkanoate)s, polyanhydrides, polyorthoesters and blends ofthese polymers.

In some embodiments, the fibrous material is sterilized prior tocombining with a resin to kill any microorganisms that may be on thefibrous material. For example, the fibrous material can be sterilized byexposing the fibrous material to radiation; by heating the fibrousmaterial under conditions and for a sufficient time to kill anymicroorganisms, e.g., boiling at normal atmospheric pressure; or byemploying chemical sterilants.

It can be advantageous to make the composite smell and/or look likenatural wood, e.g., cedarwood. For example, the fragrance, e.g., naturalwood fragrance, can be compounded into the resin used to make thecomposite. In some implementations, the fragrance is compounded directlyinto the resin as an oil. For example, the oil can be compounded intothe resin using a roll mill, e.g., a Banbury® mixer or an extruder,e.g., a twin-screw extruder with counter-rotating screws. An example ofa Banbury® mixer is the F-Series Banbury® mixer, manufactured by Farrel.An example of a twin-screw extruder is the WP ZSK 50 MEGAcompunder™,manufactured by Krupp Werner & Pfleiderer. After compounding, thescented resin can be added to the fibrous material and extruded ormolded. Alternatively, master batches of fragrance-filled resins areavailable commercially from International Flavors and Fragrances, underthe tradename PolyIff™ or from the RTP Company. In some embodiments, theamount of fragrance in the composite is between about 0.005% by weightand about 10% by weight, e.g., between about 0.1% and about 5% or 0.25%and about 2.5%.

Other natural wood fragrances include evergreen or redwood. Otherfragrances include peppermint, cherry, strawberry, peach, lime,spearmint, cinnamon, anise, basil, bergamot, black pepper, camphor,chamomile, citronella, eucalyptus, pine, fir, geranium, ginger,grapefruit, jasmine, juniperberry, lavender, lemon, mandarin, marjoram,musk, myrhh, orange, patchouli, rose, rosemary, sage, sandalwood, teatree, thyme, wintergreen, ylang ylang, vanilla, new car or mixtures ofthese fragrances. In some embodiments, the amount of fragrance in thefibrous material-fragrance combination is between about 0.005% by weightand about 20% by weight, e.g., between about 0.1% and about 5% or 0.25%and about 2.5%. Even other fragrances and methods are described U.S.Provisional Application Ser. No. 60/688,002, filed Jun. 7, 2005, theentire disclosure of which is hereby incorporated by reference herein.

Any of the fibrous material described above, e.g., the first 12 orsecond fibrous material 14, together with a resin, can be used to formarticles such as pipes, panels, decking materials, boards, housings,sheets, blocks, bricks, poles, fencing, members, doors, shutters,awnings, shades, signs, frames, window casings, backboards, flooring,tiles, railroad ties, trays, tool handles, stalls, films, wraps, tapes,boxes, baskets, racks, casings, binders, dividers, walls, mats, frames,bookcases, sculptures, chairs, tables, desks, toys, games, pallets,wharves, piers, boats, masts, septic tanks, automotive panels, computerhousings, above- and below-ground electrical casings, furniture, picnictables, benches, shelters, trays, hangers, servers, caskets, bookcovers, canes, crutches, insulation, thread, cloth, novelties, housewares and structures.

The fibrous material may be dyed before combining with the resin andcompounding to form the composites described above. In some embodiments,this dyeing can be helpful in masking or hiding the fibrous material,especially large agglomerations of the fibrous material, in molded orextruded parts. Such large agglomerations, when present in relativelyhigh concentrations, can show up as speckles in the surfaces of themolded or extruded parts.

For example, the desired fibrous material can be dyed using an acid dye,direct dye or a reactive dye. Such dyes are available from Spectra Dyes,Kearny, N.J. or Keystone Aniline Corporation, Chicago, Ill. Specificexamples of dyes include SPECTRA™ LIGHT YELLOW 2G, SPECTRACID™ YELLOW4GL CONC 200, SPECTRANYL™ RHODAMINE 8, SPECTRANYL™ NEUTRAL RED B,SPECTRAMINE™ BENZOPERPURINE, SPECTRADIAZO™ BLACK OB, SPECTRAMINE™TURQUOISE G, and SPECTRAMINE™ GREY LVL 200%, each being available fromSpectra Dyes.

In some embodiments, resin color concentrates containing pigments areblended with dyes. When such blends are then compounded with the desiredfibrous material, the fibrous material may be dyed in-situ during thecompounding. Color concentrates are available from Clariant.

EXAMPLES

Scanning electron micrographs were obtained on a JEOL 65000 fieldemission scanning electron microscope. Fiber lengths and widths (i.e.,diameters) were determined by Integrated Paper Services, Inc., Appleton,Wis., using an automated analyzer (TAPPI T271). BET surface area wasdetermined by Micromeritics Analytical Services, as were porosity andbulk density.

Example 1 Preparation of Fibrous Material from Polycoated Paper

A 1500 pound skid of virgin, half-gallon juice cartons made ofun-printed polycoated white Kraft board having a bulk density of 20lb/ft3 was obtained from International Paper. The material was cut intopieces 8¼ inches by 11 inches using a guillotine cutter and fed to aMunson rotary knife cutter, Model SC30. Model SC30 is equipped with fourrotary blades, four fixed blades, and a discharge screen having ⅛ inchopenings. The gap between the rotary and fixed blades was set toapproximately 0.020 inch. The rotary knife cutter sheared theconfetti-like pieces across the knife-edges, tearing the pieces apartand releasing a fibrous material at a rate of about one pound per hour.The fibrous material had a BET surface area of 0.9748 m2/g+/−0.0167m2/g, a porosity of 89.0437 percent and a bulk density (@0.53 psia) of0.1260 g/mL. An average length of the fibers was 1.141 mm and an averagewidth of the fibers was 0.027 mm, giving an average L/D of 42:1.Scanning electron micrographs of the fibrous material are shown in FIGS.11 and 12 at 25× magnification and 1000× magnification, respectively.

Example 2 Preparation of Fibrous Material from Bleached Kraft Board

A 1500 pound skid of virgin bleached white Kraft board having a bulkdensity of 30 lb/ft3 was obtained from International Paper. The materialwas cut into pieces 8¼ inches by 11 inches using a guillotine cutter andfed to a Munson rotary knife cutter, Model SC30. The discharge screenhad ⅛ inch openings. The gap between the rotary and fixed blades was setto approximately 0.020 inch. The rotary knife cutter sheared theconfetti-like pieces, releasing a fibrous material at a rate of aboutone pound per hour. The fibrous material had a BET surface area of1.1316 m2/g+/−0.0103 m2/g, a porosity of 88.3285 percent and a bulkdensity (@0.53 psia) of 0.1497 g/mL. An average length of the fibers was1.063 mm and an average width of the fibers was 0.0245 mm, giving anaverage L/D of 43:1. Scanning electron micrographs of the fibrousmaterial are shown in FIGS. 13 and 14 at 25× magnification and 1000×magnification, respectively.

Example 3 Preparation of Twice Sheared Fibrous Material from BleachedKraft Board

A 1500 pound skid of virgin bleached white Kraft board having a bulkdensity of 30 lb/ft3 was obtained from International Paper. The materialwas cut into pieces 8¼ inches by 11 inches using a guillotine cutter andfed to a Munson rotary knife cutter, Model SC30. The discharge screenhad 1/16 inch openings. The gap between the rotary and fixed blades wasset to approximately 0.020 inch. The rotary knife cutter theconfetti-like pieces, releasing a fibrous material at a rate of aboutone pound per hour. The material resulting from the first shearing wasfed back into the same setup described above and sheared again. Theresulting fibrous material had a BET surface area of 1.4408m2/g+/−0.0156 m2/g, a porosity of 90.8998 percent and a bulk density(@0.53 psia) of 0.1298 g/mL. An average length of the fibers was 0.891mm and an average width of the fibers was 0.026 mm, giving an averageL/D of 34:1. Scanning electron micrographs of the fibrous material areshown in FIGS. 15 and 16 at 25× magnification and 1000× magnification,respectively.

Example 4 Preparation of Thrice Sheared Fibrous Material from BleachedKraft Board

A 1500 pound skid of virgin bleached white Kraft board having a bulkdensity of 30 lb/ft3 was obtained from International Paper. The materialwas cut into pieces 8¼ inches by 11 inches using a guillotine cutter andfed to a Munson rotary knife cutter, Model SC30. The discharge screenhad ⅛ inch openings. The gap between the rotary and fixed blades was setto approximately 0.020 inch. The rotary knife cutter sheared theconfetti-like pieces across the knife-edges. The material resulting fromthe first shearing was fed back into the same setup and the screen wasreplaced with a 1/16 inch screen. This material was sheared. Thematerial resulting from the second shearing was fed back into the samesetup and the screen was replaced with a 1/32 inch screen. This materialwas sheared. The resulting fibrous material had a BET surface area of1.6897 m2/g+/−0.0155 m2/g, a porosity of 87.7163 percent and a bulkdensity (@0.53 psia) of 0.1448 g/mL. An average length of the fibers was0.824 mm and an average width of the fibers was 0.0262 mm, giving anaverage L/D of 32:1. Scanning electron micrographs of the fibrousmaterial are shown in FIGS. 17 and 18 at 25× magnification and 1000×magnification, respectively.

Other Compositions and Uses of the Fibrous Materials

Compositions can be prepared that include any of the fibrous materialsdescribed herein, including any of the fibrous materials, resins,additives or other components disclosed in U.S. Pat. Nos. 6,448,307,6,258,876, 6,207,729, 5,973,035 and 5,952,105). For example, any of thefibrous materials described herein can be combined with a solid, aliquid or a gas, e.g., a chemical or chemical formulation (in the solidor liquid state), such as a pharmaceutical (e.g., an antibiotic), anagricultural material (e.g., plant seeds, a fertilizer, herbicide orpesticide), or an enzyme or a formulation that includes enzymes.Compositions that include one or more type of bacteria or bacteria incombination with one or more enzymes can also be prepared.

Such compositions can take advantage of the fibrous material's desirableproperties. For example, any of the fibrous materials can be used toabsorb chemicals, potentially absorbing many times their own weight. Forexample, the fibrous materials can be used to absorb spilled oil, orother chemicals. Combining these fibrous materials with a microorganism,such as a bacterium, that can metabolize the oil or chemical can aid incleanup. For example, the fibrous materials can be combined withsolutions of enzymes, dried, and then used in pet bedding, or combinedwith a pharmaceutical and used for delivering a therapeutic agent, suchas a drug. If desired, the fibrous materials can be combined with adegradable polymer, e.g., polyglycolic acid, polylactic acid andcopolymers of glycolic and lactic acid. Other degradable materials thatcan be used have been discussed above.

Compositions that include fibrous materials, e.g., cellulosic orlignocellulosic materials and, e.g., chemicals or chemical formulationsin the solid, liquid or gaseous state, can be prepared, e.g., in variousimmersion, spraying, or blending apparatuses. For example, thecompositions can be prepared using ribbon blenders, cone blenders,double cone blenders, and Patterson-Kelly “V” blenders.

If desired, lignin can be removed from any of the fibrous materials thatinclude lignin, such as lignocellulosic materials. Also, if desired, thefibrous material can be sterilized to kill any microorganisms that maybe on the fibrous material. For example, the fibrous material can besterilized by exposing the fibrous material to radiation, such asinfrared radiation, ultraviolet radiation, or an ionizing radiation,such as gamma radiation. The fibrous materials can also be sterilized byheating the fibrous material under conditions and for a sufficient timeto kill any microorganisms, or by employing a chemical sterilant, suchas bleach (e.g., sodium hypochlorite), chlorhexidine, or ethylene oxide.

Any of the fibrous materials can be washed, e.g., with a liquid such aswater, to remove any undesirable impurities and/or contaminants.

In a specific application, the fibrous materials can be used as afeedstock for various microorganisms, such as yeast and bacteria, thatcan ferment or otherwise work on the fibrous materials to produce auseful material, such as a fuel, e.g., an alcohol, an organic acid, ahydrocarbon or hydrogen, or a protein.

The alcohol produced can be a monohydroxy alcohol, e.g., ethanol, or apolyhydroxy alcohol, e.g., ethylene glycol or glycerin. Examples ofalcohols that can be produced include methanol, ethanol, propanol,isopropanol, butanol, ethylene glycol, propylene glycol, 1,4-butanediol, glycerin or mixtures of these alcohols. The organic acid producedcan a monocarboxylic acid or a polycarboxylic acid. Examples of organicacids include formic acid, acetic acid, propionic acid, butyric acid,valeric acid, caproic, palmitic acid, stearic acid, oxalic acid, malonicacid, succinic acid, glutaric acid, oleic acid, linoleic acid, glycolicacid, lactic acid, γ-hydroxybutyric acid or mixtures of these acids. Thehydrocarbon produced can be, e.g., an alkane or an alkene. Examples ofhydrocarbons that can be produced include methane, ethane, propane,isobutene, pentane, n-hexane or mixtures of these hydrocarbons.

In a particular embodiment, a fiber source that includes a cellulosicand/or lignocellulosic fiber source is sheared to provide a firstfibrous material. The first fibrous material is then passed through afirst screen having an average opening size of about 1.59 mm or less (1/16 inch, 0.0625 inch) to provide a second fibrous material. The secondfibrous material is combined with a bacterium and/or enzyme. In thisparticular embodiment, the bacterium and/or enzyme is capable ofutilizing the second fibrous material directly without pre-treatment toproduce a fuel that includes hydrogen, an alcohol, an organic acidand/or a hydrocarbon.

In some embodiments, prior to combining the bacteria and/or enzyme, thefibrous material is sterilized to kill any microorganisms that may be onthe fibrous material. For example, the fibrous material can besterilized by exposing the fibrous material to radiation, such asinfrared radiation, ultraviolet radiation, or an ionizing radiation,such as gamma radiation. The microorganisms can also be killed usingchemical sterilants, such as bleach (e.g., sodium hypochlorite),chlorhexidine, or ethylene oxide.

In a particular embodiment, the cellulosic and/or lignocellulosicmaterial of the fibrous material is first broken down into lowermolecular weight sugars, which are then added to a solution of yeastand/or bacteria that ferment the lower molecular weight sugars toproduce ethanol. The cellulosic and/or lignocellulosic material can bebroken down using chemicals, such as acids or bases, by enzymes, or by acombination of the two. Chemical hydrolysis of cellulosic materials isdescribed by Bjerre, in Biotechnol. Bioeng., 49:568 (1996) and Kim inBiotechnol. Prog., 18:489 (2002), which are each hereby incorporated byreference herein in their entirety.

Bioethanol strategies are discussed by DiPardo in Journal of Outlook forBiomass Ethanol Production and Demand (EIA Forecasts), 2002; Sheehan inBiotechnology Progress, 15:8179, 1999; Martin in Enzyme MicrobesTechnology, 31:274, 2002; Greer in BioCycle, 61-65, April 2005; Lynd inMicrobiology and Molecular Biology Reviews, 66:3, 506-577, 2002;Ljungdahl et al. in U.S. Pat. No. 4,292,406; and Bellamy in U.S. Pat.No. 4,094,742, which are each hereby incorporated by reference herein intheir entirety.

Referring now to FIG. 19, a fibrous material having a low bulk densitycan be combined with a microorganism, e.g., freeze-dried yeast orbacteria, and/or a enzyme, and then revertibly densified to a fibrousmaterial composition having a higher bulk density. For example, afibrous material composition having a bulk density of 0.05 g/cm³ can bedensified by sealing the fibrous material in a relatively gasimpermeable structure, e.g., a bag made of polyethylene or a bag made ofalternating layers of polyethylene and a nylon, and then evacuating theentrapped gas, e.g., air, from the structure. After evacuation of theair from the structure, the fibrous material can have, e.g., a bulkdensity of greater than 0.3 g/cm³, e.g., 0.5 g/cm³, 0.6 g/cm³, 0.7 g/cm³or more, e.g., 0.85 g/cm³. This can be advantageous when it is desirableto transport the fibrous material to another location, e.g., a remotemanufacturing plant, where the fibrous material composition can be addedto a solution, e.g., to produce ethanol. After piercing thesubstantially gas impermeable structure, the densified fibrous materialreverts to nearly its initial bulk density, e.g., greater than 60percent of its initial bulk density, e.g., 70 percent, 80 percent, 85percent or more, e.g., 95 percent of its initial bulk density. To reducestatic electricity in the fibrous material, an anti-static agent can beadded to the fibrous material. For example, a chemical anti-staticcompound, e.g., a cationic compound, e.g., quaternary ammonium compound,can be added to the fibrous material.

In some embodiments, the structure, e.g., bag, is formed of a materialthat dissolves in a liquid, such as water. For example, the structurecan be formed from a polyvinyl alcohol so that it dissolves when incontact with a water-based system. Such embodiments allow densifiedstructures to be added directly to solutions, e.g., that include amicroorganism, without first releasing the contents of the structure,e.g., by cutting.

OTHER EMBODIMENTS

While certain embodiments have been described, other embodiments arepossible.

While some embodiments use screens to provide a desired fibrousmaterial, in some embodiments, no screens are used to make the desiredfibrous. For example, in some embodiments, a fiber source is shearedbetween a first pair of blades that defines a first gap, resulting in afirst fibrous material. The first fibrous material is then shearedbetween a second pair of blades that define a second gap that is smallerthan the first gap, resulting in a second fibrous material. Similarscreening processes can be repeated as many times as desired to producethe desired fibrous material having the desired properties.

In some embodiments, a ratio of an average length-to-diameter ratio ofthe first fibrous material to an average length-to-diameter of thesecond fibrous material is less than 1.5.

Still other embodiments are within the scope of the following claims.

What I claim is:
 1. A method comprising: mechanically treating a cellulosic or lignocellulosic material to provide a stressed material having a BET surface area of greater than about 0.25 square meters per gram and a porosity of greater than about 25 percent; and contacting the stressed material with an enzyme.
 2. The method of claim 1, where the mechanical treatment is grinding.
 3. The method of claim 2, where the grinding is stone grinding or pin grinding.
 4. The method of claim 1, where the mechanical treatment is milling.
 5. The method of claim 4, where the milling is air attrition milling.
 6. The method of claim 1, where the mechanical treatment is shearing, cutting, ripping or tearing.
 7. The method of claim 6, where the material is sheared with a rotary knife cutter.
 8. The method of claim 1, where the cellulosic or lignocellulosic material is selected from the group consisting of grasses, rice hulls, bagasse, cotton, jute, hemp, flax, bamboo, sisal, abaca, straw, corn cobs, coconut hair and mixtures thereof.
 9. The method of claim 1, where the cellulosic or lignocellulosic material is dry when it is mechanically treated.
 10. The method of claim 1, where the cellulosic or lignocellulosic material is hydrated when it is mechanically treated.
 11. The method of claim 1, where the cellulosic or lignocellulosic material is wet when it is mechanically treated.
 12. The method of claim 11, where the cellulosic or lignocellulosic material is wet with water when it is mechanically treated.
 13. The method of claim 11, where the cellulosic or lignocellulosic material is wet with isopropanol when it is mechanically treated.
 14. The method of claim 1, further comprising mechanically treating the material multiple times.
 15. The method of claim 14, where the mechanical treatments are the same.
 16. The method of claim 15, where the mechanical treatments are different.
 17. The method of claim 1, further comprising screening the mechanically treated material.
 18. The method of claim 17, further comprising multiple rounds of mechanical treatment and screening.
 19. The method of claim 17, where the screen has a average opening size of 0.79 mm or less ( 1/32 inch, 0.03125 inch).
 20. The method of claim 1, where the mechanically treated material has a length to diameter ratio of 8:1.
 21. The method of claim 1, where the mechanically treated material has a length to diameter ratio of 10:1.
 22. The method of claim 1, where the mechanically treated material has a length to diameter ratio of 25:1.
 23. The method of claim 1, where the mechanically treated material has a length to diameter ratio of 50:1.
 24. The method of claim 1, where the mechanically treated material has an average length of about 0.5 to about 2.5 mm.
 25. The method of claim 1, where the mechanically treated material has an average length of about 0.75 to about 1.0 mm.
 26. The method of claim 1, where the mechanically treated material has an average width of about 5 um to about 50 um.
 27. The method of claim 1, where the mechanically treated material has an average width of about 10 um to about 30 um.
 28. The method of claim 1, where the mechanically treated material has a BET surface area of 0.5 square meters per gram.
 29. The method of claim 1, where the mechanically treated material has a BET surface area of 1.0 square meters per gram.
 30. The method of claim 1, where the mechanically treated material has a BET surface area of 1.5 square meters per gram.
 31. The method of claim 1, where the mechanically treated material has a BET surface area of 1.75 square meters per gram.
 32. The method of claim 1, where the mechanically treated material has a BET surface area of 2.5 square meters per gram.
 33. The method of claim 1, where the mechanically treated material has a BET surface area of 10.0 square meters per gram.
 34. The method of claim 1, where the mechanically treated material has a porosity of greater than about 50 percent.
 35. The method of claim 1, where the mechanically treated material has a porosity of greater than about 75 percent.
 36. The method of claim 1, where the mechanically treated material has a porosity of greater than about 85 percent.
 37. The method of claim 1, where the mechanically treated material has a porosity of greater than about 90 percent. 